Apparatus for arranging and soldering together electrode sets for lead accumulators

ABSTRACT

Apparatus for producing finished plate sets constituting a cell in a lead-acid accumulator. Positive and negative plate electrodes and separator sheets, in proper sequence and number, are fed in at station A, arranged and adjusted positionally relative to one another at station B, and inverted so that the plate lugs are fluxed at station C. The lugs are inserted into mold troughs carried by a lower chain system at station D, and the pole bridges with connecting terminals or external terminal posts formed integrally therewith during the travel to station E, after which the mold troughs are removed and the finished plate set is removed as a sub-assembly at station F.

Unite States Patent [191 [111 3,734,167 ()dman 1 May 22, 1973 54]APPARATUS FOR ARRANGING AND 3,544,057 12/1970 Coward ..136/176 xSOLBERING TOGETHER ELECTRODE 3,616,845 11/1911 Farmer ..164/333 SETS FORLEAD ACCUMULATORS Tor Axel Odman, Stockholm, Sweden Aktiebolaget SwedenFiled: Dec. 13, 1971 Appl. No.: 207,336

Inventor:

Assignee: Tudor, Stockholm,

References Cited UNITED STATES PATENTS Federici ..136/176 X PrimaryExaminer-J. Spencer Overholser Assistant Examiner-V. K. RisingAtt0rney-A. Donald Messenheimer [57] ABSTRACT Apparatus for producingfinished plate sets constituting a cell in a lead-acid accumulator.Positive and negative plate electrodes and separator sheets, in propersequence and number, are fed in at station A, arranged and adjustedpositionally relative to one another at station B, and inverted so thatthe plate lugs are fluxed at station C. The lugs are inserted into moldtroughs carried by a lower chain system at station D, and the polebridges with connecting terminals or external terminal posts formedintegrally therewith during the travel to station E, after which themold troughs are removed and the finished plate set is removed as asub-assembly at station F.

12 Claims, 18 Drawing; Figures PATENTED #9122 I975 SHEET as 11? mAPPARATUS FOR ARRANGING AND SOLDERING TOGETHER ELECTRODE SETS FOR LEADACCUMULATORS This invention relates to apparatus used for arranging andsoldering together electrode plate sets for lead-acid electricaccumulators.

The electrode plate sets conventionally comprise a group of positive andnegative plate electrodes closely spaced to each other. In fabricatingan electrode plate set, it is necessary that the requisite number ofnegative and positive plate electrodes are laid alternately one abovethe other and separated by sheets of an insulating material that hasmicroporous openings which allow for the circulation of electrolytebetween the positive and negative electrodes.

The positive plates in a plate set are all connected together by a polebridge which connects with lugs on each positive plate. The negativeplate electrodes are connected together by a similar pole bridge. Theseplate lugs are oriented in such a way that the soldering together of thepositive or negative lugs,respectively, can take place. Customarily, thepositive plate lugs are located near the upper edge at one side of theplate set, while the negative plate lugs are located at the other sideof the upper edge of the plate set.

The separator sheets usually have a somewhat larger area than the platesso that the edges of the separator sheets project beyond the edges ofthe electrode plates over the whole extent of the electrode plate so asto prevent short-circuiting. During manufacture of the plate sets as asub-assembly, the problem has always arisen of locating the plates andseparators in the correct position so that the marginal edges areproperly located relative to one another. In the-past, complicatedfittings jigs and fixtures have been used to enable this operation to becarried out.

Even after the electrode plate set components are arranged and locatedproperly relative to one another, there still remains the step ofproviding the pole bridge and associated terminal with each lug set.

It is a major object of the present invention to provide a novelapparatus for automatically forming on the plate lugs the necessary polebridge and connectors.

A further object of the invention is to provide a novel apparatuswherein the positive and negative plates and separator sheets may belaid alternately, one above the other, on a plate set holder, andthereafter the necessary adjustments are made for arranging the marginaledges of the electrodes and separator sheets during the course ofoperation of the machine.

A still further object-of the invention resides in providing a novelmachine wherein the assembled electrode plate sets are inverted to bepassed through a flux station and into a traveling mold trough whereinthe respective pole bridges and terminals are formed as the plate setpasses through the machine.

Another object is to provide a novel mold trough arrangement wherein themolten lead alloy which serves as the pole bridge and terminal is pouredinto the mold trough over an inclined plane in such way as to avoidburning of the plate electrode lugs and to assure a good electrical andmechanical connection thereto.

These and other objects of the invention will become more fully apparentfrom the claims and from the description as it proceeds in connectionwith the appended drawings wherein:

FIG. 1 is a front view diagrammatically showing the apparatus of thepresent invention;

FIG. 2 is a right end view of FIG. 1;

FIG. 3 is a top plan view of FIG. 1;

FIG. 4 is a left end view to an enlarged scale of the upper portion ofthe apparatus of FIG. 1 when the electrode plates and the separator arealigned;

FIG. 5 is a top view of that portion of the apparatus shown in FIG. 4with the arrow indicating the direction of movement of the electrodeplate assembly;

FIG. 6 is a right end view ofthe apparatus shown in FIG. 5;

FIG. 7 is a front view of the flux zone;

FIG. 8 is a top plan view of the zone shown in FIG.

FIG. 9 is a right end view of the zone shown in FIG.

FIG. 10 is a front view of the casting mold for a pole bridge orconnecting strap;

FIG. 11 is a top plan view of the casting mold of FIG. 10;

FIGS. 12 and 13 show a casting mold of the same kind as shown in FIGS.10 and 11, but the connecting parts with pole bridges in this case areformed with a pole adapted to serve as an external battery terminal;

FIG. 14 is a diagrammatic front view of the casting section of theapparatus of the present invention having the electrode plate assemblyinverted so that the lugs extend down into the casting mold;

FIG. 15 is a partial left side view of the casting section shown in FIG.14;

FIG. 16 is a top plan view taken along line 16 of FIG. 15; and

FIGS. 17 and 18 are front and side elevations showing diagrammaticallythe way of pouring the molten lead alloy into the mold troughs inaccordance with the present invention.

Lead-acid accumulators of the type having parallel positive and negativeplate electrodes and a liquid electrolyte are well known. In each cell,a group of three or more positive electrodes are joined together by polebridges which customarily consist of a body of lead or lead alloy havinga substantial cross-sectional area to provide a low electricalresistance to current flow between the electrodes and the pole bridgeterminals. An equal number of negative electrodes are similarly joinedby negative pole bridges. The electrodes are kept from contacting oneanotherby separators which usually comprise a microporous sheet ofmaterial having a good resistance against destruction due to movement ofthe abutting electrodes.

The positive and negative electrodes may be of the type disclosed inU.S. Pat. No. 3,296,028. A typical prior art separator sheet isdisclosed in U.S. Pat. No. 3,055,966. The positive and negativeelectrodes and separator sheets are joined together as a unitary, rigidsub-assembly and serve as one cell of a multiple-cell battery, as shownfor example in U.S. Pat. No. 3,484,299.

Referring now to FIGS. 1-3, and more particularly to FIG. 1 which showsdiagrammatically several vertical and horizontal frame members forsupporting an upper sprocket wheel pair 7 and 8 and a lower sprocketwheel pair 7' and 8', the upper sprocket wheels 7 and 8 drive acontinuous chain system 1 which has connected thereto a plurality ofcell sub-assembly holders 18. Only one such cell sub-assembly holder 18is illustrated in FIG. 1 for purposes of simplification of the drawings.In actual practice, a separate holder 18 is provided for each cellsub-assembly. The chain system 1 moves the cell sub-assembly holders 18from station A illustrated in FIG. 1 in a direction as indicated by thearrows on FIG. 1 around sprocket 8 and along the lower length of chain11, at which time the cell sub-assembly holder 18 is in an invertedposition. The cell sub-assembly holder 18 is illustrated in greaterdetail in FIG. 14 where it is there shown in this inverted position. Thecell subassembly holder 18 essentially consists of a plate support arm 3and a movable holding member 4 which hold the electrodes and separatorsof the cell subassembly 17 in place on the cell sub-assembly holder 18during the time the cell sub-assembly traverses along the lower path ofthe chain system 1, at which time it is in its inverted position.

Referring now to FIG. 1, at station A when a plate holder 18 is at itshorizontal position, the positive and negative electrodes with theseparators therebetween are laid on the plate support arm 3. As theupper chain system 1 advances, the cell sub-assembly moves to station Band thereafter through stations C, D, and E to a final station F wherethe sub-assembly is removed from the machine.

A lower chain system 2 carries a plurality of holders 22 for castingmolds, which will be described below.

Both chain systems 1 and 2 are of like construction with the two chainstraveling concomitantly through a single drive system shown in FIG. 1 asincluding a motor 15, an intermittent drive mechanism 16, and drivechain 13 which interconnects the upper chain system 1 and the lowerchain system 2 with sprocket wheel which is driven by drive chain 14.Chain 13 does not operate continuously but instead advances the chainsystems 1 and 2 a distance equal in length to the distance between twoadjacent cell sub-assembly holders 18 during a given time and thereafterstands still for about one-third of this time. During the standstillperiod, a number of actions take place, which will be described below.

With continued reference to FIGS. 1 through 3, the positive and negativeelectrodes and separators which constitute the cell sub-assembly 17 arefed as separate elements into the machine when a holder 18 is in asubstantially horizontal position, as illustrated at station A inFIG. 1. The marginal edges need not be accurately aligned. The cellsub-assembly elements follow the chain system 1 over sprocket 7 tostation B where the electrodes and separators are standing on theirbottom edges with lugs 19 and 19', which are conventionally formed onthe positive and negative electrodes on opposite sides, respectively, ofthe top edge of the electrodes, extending upwardly as illustrated inFIG. 4.

At station B is a plate adjusting mechanism which is illustrated inFIGS. 4 through 6. This adjusting mechanism arranges and aligns theelectrodes and the separators into the correct position in relation toone another. When the electrodes and separators leave station B in theirupright position, they are gripped firmly by movable holding member 4and conveyed over sprocket 8, after which they are turned over into aninverted position with lugs 19 and 19' extending downwardly as the lugspass into station C.

With continued reference to FIGS. 4 through 6, which show the adjustingmechanism fixedly located at station B, the electrodes are delivered tothe in-feed side of station B in a vertical plane and are oriented sothat the large electrode area faces the direction of movement. Since themarginal edges of the electrodes and separators are not aligned at thetime of being fed into the machine at station A, it is necessary toeffect a lateral adjusting movement of the plates and separatorsrelative to each other in a direction transverse to the direction of thetravel of the holders l8 and the chain system 1. At station B, theelectrodes and separators are not held tightly in the holder 18, butinstead rest between plate support arm 3 and movable holding member 4which are like loose jaws. The plates and separators are supported onbaseplate 20 of the holder 18, which is shown in FIGS. 4, 5, and 6. Theelectrodes, having lugs 19 on their upper edges, have projections 21 ontheir lower edges, and the electrodes having lugs 19 have similarprojections 21'. The baseplate 20 is provided with four parallel grooves22 which are designed to catch the projections 21 and 21' during thetransverse movement of baseplate 20 at station E. It will be apparent,however, that the electrodes could have grooves and baseplate 20 haveprojections, if desired.

Baseplate 20 is provided with a pair of rollers 23 on opposite sidesthereof, the rollers being subjected to the undulations on the insidesurfaces of fixed members 24 and 25 located at station B. The chainsystem 1 moves in the direction of the arrow shown in FIG. 5. Themembers 24 and 25 have undulations 24 and 25' which act as cam surfacesagainst which rollers 23 engage. The undulations 24 and 25 are soconstructed that the travel of the movement transverse to the directionof the movement of the chain system 1 is greater at the in-feed side ofstation E and decreases successively and goes to zero at the end of theadjusting region. During repeated to and fro motion of baseplate 20transverse to the direction of chain system 1, the projections 21 and21-of the positive and negative electrodes catch into the grooves 22 inthe baseplate 20 to give perfect alignment of the bottoms of theelectrodes.

With continued reference to FIGS. 4, 5, and 6, the arrangement of thepositive and negative electrodes in relation to one another is furtherfacilitated by the lugs 19 and 19 being controlled during the adjustmentprocedures by four members 26, 27, 28, and 29 which form wedge-shapedopenings 30 which, as shown at the right-hand end of FIG. 5, haverelatively wide gaps and gradually taper in conformity with thenarrowing of the undulations 24' and 25 in plates 24 and 25 to narrowchannels 31 at the left side of FIG. 5. The openings at 31 provide guidesurfaces to assure that lugs 19 and 19, and hence the upper portion ofthe positive and negative electrodes, are properly positioned.

For arranging the separators 34, which are usually thin sheets of firmmaterial, the adjusting mechanism is provided with a pair of side plates32 and 33, one on each side of the path of the electrodes. The sideplates 32 and 33 are located above the base-plate 20 and below the lugadjusting members 26-29. With the movement of the electrode sub-assemblyfrom side to side, as caused by the to and fro movement of baseplate 20,the projecting edges of the separator sheets 34 are pushed transverselyinto their correct position in the electrode sub-assembly by side plates32 and 33.

Since the separators 34 are somewhat wider than the electrodes, the sideplates 32 and 33 are appropriately positioned. The electrodes are soarranged that the separators 34 extend slightly beyond the outside ofthe electrodes and preferably by an equal amount on each side. When thecell sub-assembly has completed its travel through the adjustingmechanism shown in FIGS. 4 through 6, then the transverse motion ofbaseplate cases, and the lugs 19 are passing through channel 31. Thecell sub-assembly is then held firmly in the holder 18 with the closureof movable holding member 4 (see FIGS. 1 and 14). Holding member 4 isnot released until the cell sub-assembly 17 is removed from the machineat station F.

After leaving station B, the cell sub-assembly 17 in holder 18 isadvanced to station C where the lugs are dipped into the flux. The fluxstation may comprise apparatus as illustrated in FIGS. 7, 8, and 9.

The lugs 19 and 19 extend downwardly, as best shown in FIG. 9. Here andwith their continued movement in the beginning of the lower straightstretch, the lugs 19 and 19' dip into troughs 35 and 35 which are filledwith flux. Flux is fed continuously through feedpipes 36 from commonpipe 37 which is connected to the output side of a pump (not shown).

The free flux surface in troughs 35 and 35' is kept substantiallyhorizontal since the troughs 35 are wide relative to the width of thelugs 19 and 19' and the apertures 38 in the troughs. The width of theapertures 38 is such that the lugs 19 and 19' can pass with someclearance. Flux flows into the outer return troughs 39 and on throughdischarge pipes 40 and 41 back to a flux reservoir (not shown) to whichthe pump is connected.

Referring to FIGS. 10 and 11, casting troughs 42 are illustrated.Casting troughs 42 are carried along with the mating mold component 43by the casting mold holders 22 shown in FIG. 1. In casting troughs 42, arow of lugs 19 or 19 are soldered together to form what is commonlyreferred to as pole bridges. In the illustrated embodiment, a separatecasting trough 42, which term is intended to embrace also the moldcomponent 43, is provided on each side of the plate subassemblies.

The casting troughs 42 and 42' into which lugs 19 and 19' extend arecarried by mold holders 22 and 22' which are driven by chain drive 2 andengagement first occurs at station D (FIG. 1). The pole bridge whichconnects the respective lugs 19 or 19' on one electrode set is formed ina casting trough 42, as illustrated in FIGS. 10-18. The casting trough42 is in turn fixedly connected, preferably by means of hard soldering,to the other mold components 43, 44, in which a connector lug 45 isformed, as illustrated in FIGS. 10 and 11. Lug 45 is used as a terminalfor connection with another cell in the same battery and may have anydesired configuration. A terminal pillar, or external terminal, 46 isformed by the mold, as illustrated in FIGS. 12 and 13.

In either case, the molding trough 42 is the same and is madethin-walled so that the amount of heat required for heating it iscomparatively unimportant by comparison with the heat required for aheavy mold with thick walls.

A light, or thin-walled, casting mold 42 made of thin sheet metal inaccordance with one of the features of this invention, makes it possiblefor castings to be produced without considerable heating of the mold.For example, the specific heat in the case of a mold of thin sheet metalis so small that the specific heat of the lead is sufficient both forthe heating and for the temperature rise required to take place at thelugs 19 for a satisfactory soldering together to be effected. A castingprocess which does not require a preliminary heating of the casting moldor trough makes possible a quick starting of the machine, and no extrawaiting time is required after a stoppage of work.

The actual casting which mechanically and electrically connects theplate electrodes of the positive electrode set together and thecorresponding negative electrode set together by equipping them with aconnecting member, known as the pole bridge, will now be described. Whenthe plate set sub-assembly has passed the flux apparatus at station C,the set holders 18 and the mold holders 22 come in on the commonparallel straight stretch at station D in FIG. 1, along which stretchthey move concomitantly. The mold troughs 42-43 rise toward theconnecting lugs 19 and 19, respectively, of the plate sets 17. Correctrelative positioning for casting is achieved, as will be describedbelow.

With reference to FIGS. 14-16, each mold holder 22 has an indexingmember 47 (FIG. 16) with two molds 42 on opposite sides of the electrodesub-assembly and is therefore movable vertically in relation to thefixed cam surface 48 (FIG. 14) which is located adjacent the lower chainsystem 2. The fixing and raising of the molds is effected by means of acurved member having cam surface 48. The curved member acts on a roller49 which is supported at the ends of a pair of spaced lifting arms 50 tolift the mold indexing member 47 by means of a spring 51. When thelifting end position is reached, two conical pins 52, carried byindexing member 47, enter two corresponding holes in a plate 53 which isfixedly connected to the set holder 18. The connection between theholder 18 and the mold trough 42 is thereby held fast and fixed duringthe advancement of the chain systems 1 and 2 from the casting station Duntil the mold trough 42 drops away at station E. The vertical positionof the mold trough 42, which starts in relation to the lugs 19 and 19'of the plateset subassembly, is controlled in the illustrated example byadjusting the height of the conical pins 52; this adjustment controlsthe distance between the ends of the contact lugs 19 and 19' and thebottom of "their respective mold trough 42, as desired.

Lead is fed from melting pots into the mold trough 42 along a side edge,preferably on each side of the machine. The melting pots are providedwith a pipe 54 (FIG. 18) which extends from the pot (not shown) as faras the mold trough 42. A needle valve (not shown- ),acted on by a magnetin a known manner, opens the connection between the pot and the pipe,and the times of opening are so set that the correct quantity of lead issupplied to the different mold troughs 42.

With reference to FIGS. 17 and 18, in order to pre vent the lugs 19,which during the casting are thrust down in the mold trough 42, fromburning and to prevent other accidents, the molten lead 55 is caused torun over a member having an inclined surface 56 down into the moldtrough 42. It is hereby ensured first of all that the lead always has torun down into the mold trough along its side wall edge 57, and furtherthat the lead alloy always runs into the mold at the same angle,independently of variations in the rate of flow of the lead alloy. Theangle is so set that the danger of the lugs 19 burning is minimized; thedirection is such that it faces the side edge of the lugs 19.

The inclined plane member 56 is preferably made of material with a lowheat conductivity, for instance, ceramic material, as no heating isrequired.

The inclined ceramic member 56 is supported on a resilient handle member58 which has one end fixed to the frame of the apparatus so that theceramic member 56 has a bottom surface which lies against the upper edgeof the sidewall of the mold trough 42 with a slight force. It isfurthermore given a rounding-off 59 at one end so that it can be raisedup by the leading edge of the mold trough 42. The other end 60 of theceramic member 56 is designed as a transverse scraper to spring quicklyback after the mold passes, so that any lead oxide remaining is shakenoff.

After the filling of lead into the mold trough 42 at station D in FIG.1, the set holders 18 and mold holders 22 move concomitantly and followone another while they are fixedly coupled together by means of pins 52and plates 53 (FIG. 14). During the movement on the common straightstretch between D and E, there takes place the solidifying of the leadalloy which effects the soldering together of the lugs 19 and 19',respectively, with lead alloy melt.

At station E, the temperature in the mold troughs 42 falls below themelting temperature of lead, so that the mold can be separated from thelugs 19 with the now finished pole bridges formed.

After the mold troughs 42 have separated from the plate set holder 18 bya downwardmovement of cast mold holders as a result of the action of camsurface 48 and roller 49, the plate set sub-assembly 17 remains with itsset holder 18 until the position at station F in FIG. 1 is reached.While the standstill occurs at station F, the set holders l8 loosentheir grip on the plate set sub-assembly 17 through their releasemechanism being acted on by a magnet (not shown here). The finishedplate set sub-assembly can be caused to slide away as, for example, bymeans of a conveyor belt.

In summary, the apparatus of the present invention is effective to forma rigid sub-assembly of positive and negative electrode plates, togetherwith the interleaved separator sheets, which when placed in thecompartment of a battery having a liquid electrolyte, constitute a cellof the battery. The apparatus of the present invention is effective,when the positive plates, the negative plates, and the separator sheetsare placed in the right order relative to one another, to first adjustthe marginal edges of these components while they are held loosely inviselike jaws so that the projections on the bottom edges of thepositive and negative plate electrodes are in alignment, the lugs on theupper edge surface of the positive plate electrodes are in a first line,the lugs on the negative plate electrodes are in a second line, and theseparator sheets are adjusted so as to fully protect the adjacentpositive and negative plate electrodes from contacting one another.Thereafter, the electrodes and separators are held firmly together as aunitary body and inverted so that the lugs are facing downwardly. Thenthe lugs are passed through a flux station and then immediately intocasting mold troughs. The mold troughs are mounted for concomitantmovement with the electrodes troughs so that while the pole bridges arebeing soldered on the plate electrodes are being formed, the electrodeplate subassemblies and the mold troughs move from station D to stationE. At that time, the mold trough drops below the electrode platesub-assembly, which then advances to station F at which time it isremoved from the machine.

The present invention may be embodied in other specific forms withoutdeparting from the spirit or essential characteristics thereof. Thepresently disclosed embodiments are therefore to'be considered in allrespects as illustrative and not restrictive, the scope of the inventionbeing indicated by the appended claims rather than by the foregoingdescription, and all changes which come within the meaning and range ofequivalency of the claims are therefore intended to be embraced therein.

What is claimed and intended to be covered by Letters Patent is:

1. Apparatus for joining the positive plate electrodes and the negativeplate electrodes by means of the casting of a body of a lead alloy ontolugs at an upper edge of said electrodes, the lugs on the positiveelectrodes being at one side and the lugs on the negative electrodesbeing on the other side of a sub-assembly comprising a plurality ofpositive electrodes and a plurality of negative electrodes, saidapparatus comprising:

means for clamping positive and negative electrodes together withseparator sheets in a fixed position with the lugs on the positiveelectrodes in a first line and the lugs on the negative electrodes in asecond line;

means for applying flux to said lugs;

means for holding said electrodes so that said lugs extend downwardlyand advancing said electrodes along a predetermined path;

casting mold means including troughs which have an open upper surfaceadapted to receive the positive electrode lugs in one trough and thenegative electrode lugs in another trough;

means advancing said casting mold means along a path parallel to saidpredetermined path concomitantly with the advancement of saidelectrodes, said casting mold means and said electrode lugs being sopositioned during said concomitant advancement that the electrode lugsextend inside their respective troughs;

means for supplying molten lead alloy into said casting troughs whilesaid lugs are positioned in said casting troughs; and

means for separating said electrodes from said casting mold means aftersaid lead alloy has solidified onto said lugs.

2. Apparatus as defined in claim 1 wherein said means for applyingmolten lead alloy into said casting troughs includes a conduit having anopen end located above the trough open upper surface and a member havingan inclined surface extending between said conduit open end and theupper trough surface whereby flowing casting lead is supplied in adirection facing the edges of said lugs and caused to run over theinclined surface into the trough in order that the running-in angle ofthe lead alloy is substantially independent of the flow rate of themolten lead alloy.

3. Apparatus as defined in claim 2 wherein said member having aninclined surface is of a ceramic material having low heat conductivity.

4. Apparatus as defined in claim 2 further having a resilient mountingmeans for said member having an inclined surface; said last-mentionedmember has a rounded surface on one end adapted to engage the leadingedge of the trough as the trough comes into alignment with said memberand be raised against the bias force of said resilient mounting means.

5. Apparatus as defined in claim 4 wherein said member having aninclined surface has a transverse scraper surface at the other end tothereby aid in removing any lead oxide on the abutting surface of saidtrough.

6. Apparatus as defined in claim 1 wherein the troughs are made of sheetmetal sufficiently thin so that the specific heat of the molten leadalloy is adequate to cause the temperature required to take place at thelugs for a satisfactory bond and without preliminary heating of thetrough.

7. Apparatus as defined in claim 1 wherein said means for clampingpositive and negative electrodes together with separator sheetscomprises:

holder means having a first member for supporting bottom edges of saidelectrodes and separator sheets;

said first member and said electrodes having mating grooves andprojections; and drive means for advancing said holder means through analignment station while said clamping means holds said electrodes andseparator sheets loosely;

said alignment station comprising means for effecting a relative to andfro movement among said loosely held electrodes and separator sheets ina direction transverse to the direction of advancement of said holdermeans through said alignment station to thereby cause the projections tofit into said grooves and align bottom and side edges of said electrodesrelative to each other.

8. Apparatus as claimed in claim 7 wherein said to and fro movementeffecting means comprises a pair of fixed, spaced members having facingundulating cam surfaces; and

said first member has a pair of rollers on opposite sides thereof whichengage the cam surfaces as said first member is driven through thealignment station to thereby impart a reciprocating motion directedsubstantially perpendicularly to the direction of advancement of saidsub-assembly.

9. Apparatus as claimed in claim 7 wherein:

the positive electrodes have lugs on the upper edge at one side thereofand the negative electrodes have lugs on the other side thereof; and

said alignment station further comprises:

fixed guide means having a pair of channels through which said lugs passas the holder means advances through said alignment station;

each of said channels containing a pair of facing surfaces adapted toengage opposite sides of the respective lug;

said facing surfaces being spaced apart by a distance substantiallygreater than the width of said lugs at the in-feed side of saidalignment station, and gradually converging to a spacing only veryslightly greater than the width of said lugs at the out-feed side ofsaid alignment station.

10. Apparatus as defined in claim 7 wherein said alignment stationfurther comprises:

a pair of fixed side plates which are located above said first memberand adapted to engage side edges of said separator sheets; said sideplates being spaced apart by a distance substantially greater than thewidth of said separator sheets at the in-feed side of said alignmentstation and gradually converging to a spacing substantially equal to thewidth of said separator sheets at the out-feed side of said alignmentstation. 11. Apparatus as defined in claim 8 wherein: the positiveelectrodes have lugs on an upper edge at one side thereof and thenegative electrodes have lugs on the other said thereof; and saidalignment station further comprises:

fixed guide means having a pair of channels through which said lugs passas the holder means advances through said alignment station; each ofsaid channels containing a pair of facing surfaces adapted to engageopposite sides of the respective lug; said facing surfaces being spacedapart by a distance substantially greater than the width of said lugs atthe in-feed side of said alignment station, and gradually converging toa spacing only very slightly greater than the width of said lugs at theout-feed side of said alignment station; and a pair of fixed side plateswhich are located above said first member and below said fixed guidemeans and adapted to engage side edges of said separator sheets; saidside plates being spaced apart by a distance substantially greater thanthe width of said separator sheets at the in-feed side of said alignmentstation and gradually converging to a spacing substantially equal to thewidth of said separator sheets at the outfeed side of said alignmentstation. 12. Apparatus as defined in claim 11 wherein said means forsupplying molten lead alloy into said casting troughs includes a conduithaving an open end located above the trough open upper surface and amember having an inclined surface extending between said con duit openend and the upper trough surface whereby flowing casting lead issupplied in a direction facing the edges of said lugs and caused to runover the inclined surface into the trough in order that the running-inangle of the lead is substantiallyindependent of the flow rate of themolten lead alloy;

means for resiliently mounting said inclined surface member; saidlast-mentioned member having a rounded surface on one end adapted toengage the leading edge of the trough after the trough comes intoalignment with said member and be raised against the bias force of saidresilient mounting means and a transverse scraper surface at the otherend to thereby aid in removing any lead oxide on the abutting surface ofsaid trough; and the troughs are made of sheet metal sufficiently thinso that the specific heat of the molten lead alloy is adequate to causethe temperature required to take place at the lugs for a satisfactorybond and without preliminary heating of the trough.

1. Apparatus for joining the positive plate electrodes and the negativeplate electrodes by means of the casting of a body of a lead alloy ontolugs at an upper edge of said electrodes, the lugs on the positiveelectrodes being at one side and the lugs on the negative electrodesbeing on the other side of a sub-assembly comprising a plurality ofpositive electrodes and a plurality of negative electrodes, saidapparatus comprising: means for clamping positive and negativeelectrodes together with separator sheets in a fixed position with thelugs on the positive electrodes in a first line and the lugs on thenegative electrodes in a second line; means for applying flux to saidlugs; means for holding said electrodes so that said lugs extenddownwardly and advancing said electrodes along a predetermined path;casting mold means including troughs which have an open upper surfaceadapted to receive the positive electrode lugs in one trough and thenegative electrode lugs in another trough; means advancing said castingmold means along a path parallel to said predetermined pathconcomitantly with the advancement of said electrodes, said casting moldmeans and said electrode lugs being so positioned during saidconcomitant advancement that the electrode lugs extend inside theirrespective troughs; means for supplying molten lead alloy into saidcasting troughs while said lugs are positioned in said casting troughs;and means for separating said electrodes from said casting mold meansafter said lead alloy has solidified onto said lugs.
 2. Apparatus asdefined in claim 1 wherein said means for applying molten lead alloyinto said casting troughs includes a conduit having an open end locatedabove the trough open upper sUrface and a member having an inclinedsurface extending between said conduit open end and the upper troughsurface whereby flowing casting lead is supplied in a direction facingthe edges of said lugs and caused to run over the inclined surface intothe trough in order that the running-in angle of the lead alloy issubstantially independent of the flow rate of the molten lead alloy. 3.Apparatus as defined in claim 2 wherein said member having an inclinedsurface is of a ceramic material having low heat conductivity. 4.Apparatus as defined in claim 2 further having a resilient mountingmeans for said member having an inclined surface; said last-mentionedmember has a rounded surface on one end adapted to engage the leadingedge of the trough as the trough comes into alignment with said memberand be raised against the bias force of said resilient mounting means.5. Apparatus as defined in claim 4 wherein said member having aninclined surface has a transverse scraper surface at the other end tothereby aid in removing any lead oxide on the abutting surface of saidtrough.
 6. Apparatus as defined in claim 1 wherein the troughs are madeof sheet metal sufficiently thin so that the specific heat of the moltenlead alloy is adequate to cause the temperature required to take placeat the lugs for a satisfactory bond and without preliminary heating ofthe trough.
 7. Apparatus as defined in claim 1 wherein said means forclamping positive and negative electrodes together with separator sheetscomprises: holder means having a first member for supporting bottomedges of said electrodes and separator sheets; said first member andsaid electrodes having mating grooves and projections; and drive meansfor advancing said holder means through an alignment station while saidclamping means holds said electrodes and separator sheets loosely; saidalignment station comprising means for effecting a relative to and fromovement among said loosely held electrodes and separator sheets in adirection transverse to the direction of advancement of said holdermeans through said alignment station to thereby cause the projections tofit into said grooves and align bottom and side edges of said electrodesrelative to each other.
 8. Apparatus as claimed in claim 7 wherein saidto and fro movement effecting means comprises a pair of fixed, spacedmembers having facing undulating cam surfaces; and said first member hasa pair of rollers on opposite sides thereof which engage the camsurfaces as said first member is driven through the alignment station tothereby impart a reciprocating motion directed substantiallyperpendicularly to the direction of advancement of said sub-assembly. 9.Apparatus as claimed in claim 7 wherein: the positive electrodes havelugs on the upper edge at one side thereof and the negative electrodeshave lugs on the other side thereof; and said alignment station furthercomprises: fixed guide means having a pair of channels through whichsaid lugs pass as the holder means advances through said alignmentstation; each of said channels containing a pair of facing surfacesadapted to engage opposite sides of the respective lug; said facingsurfaces being spaced apart by a distance substantially greater than thewidth of said lugs at the in-feed side of said alignment station, andgradually converging to a spacing only very slightly greater than thewidth of said lugs at the out-feed side of said alignment station. 10.Apparatus as defined in claim 7 wherein said alignment station furthercomprises: a pair of fixed side plates which are located above saidfirst member and adapted to engage side edges of said separator sheets;said side plates being spaced apart by a distance substantially greaterthan the width of said separator sheets at the in-feed side of saidalignment station and gradually converging to a spacing sub-stantiallyequal to the width of said separator sheets at the out-feed side of saidalignment station.
 11. Apparatus as defined in claim 8 wherein: thepositive electrodes have lugs on an upper edge at one side thereof andthe negative electrodes have lugs on the other said thereof; and saidalignment station further comprises: fixed guide means having a pair ofchannels through which said lugs pass as the holder means advancesthrough said alignment station; each of said channels containing a pairof facing surfaces adapted to engage opposite sides of the respectivelug; said facing surfaces being spaced apart by a distance substantiallygreater than the width of said lugs at the in-feed side of saidalignment station, and gradually converging to a spacing only veryslightly greater than the width of said lugs at the out-feed side ofsaid alignment station; and a pair of fixed side plates which arelocated above said first member and below said fixed guide means andadapted to engage side edges of said separator sheets; said side platesbeing spaced apart by a distance substantially greater than the width ofsaid separator sheets at the in-feed side of said alignment station andgradually converging to a spacing substantially equal to the width ofsaid separator sheets at the outfeed side of said alignment station. 12.Apparatus as defined in claim 11 wherein said means for supplying moltenlead alloy into said casting troughs includes a conduit having an openend located above the trough open upper surface and a member having aninclined surface extending between said conduit open end and the uppertrough surface whereby flowing casting lead is supplied in a directionfacing the edges of said lugs and caused to run over the inclinedsurface into the trough in order that the running-in angle of the leadis substantially independent of the flow rate of the molten lead alloy;means for resiliently mounting said inclined surface member; saidlast-mentioned member having a rounded surface on one end adapted toengage the leading edge of the trough after the trough comes intoalignment with said member and be raised against the bias force of saidresilient mounting means and a transverse scraper surface at the otherend to thereby aid in removing any lead oxide on the abutting surface ofsaid trough; and the troughs are made of sheet metal sufficiently thinso that the specific heat of the molten lead alloy is adequate to causethe temperature required to take place at the lugs for a satisfactorybond and without preliminary heating of the trough.